textproduct: Quad Cities

KEY MESSAGES

- We continue with multiple days of severe weather risks the rest of the week, with an Enhanced Risk (level 3 of 5) for severe storms for parts of the area today and again Friday, along with a Slight Risk (level 2 of 5) Wednesday.

- Above normal temperatures will continue through Friday. - Potential for frost/freeze conditions Saturday night and especially Sunday night.

SHORT TERM /THROUGH TONIGHT/

Issued at 334 AM CDT Tue Apr 14 2026

Residual outflow boundary from decaying WI MCS extends roughly near a line from Independence, Iowa to Monticello, Iowa to near Sterling, Illinois early this morning. The boundary is markedly slowing as organized convection earlier in WI continues to diminish. 00Z DVN RAOB sampled a well defined EML, which until recently has largely kept precipitation at bay except for portions of Jo Daviess and Stephenson counties atop the lingering low level cool pool north of the outflow boundary. However, low level water vapor imagery loop appears to suggest a cirrus tag denoting a weak impulse lifting up across the area. This along with increasing low to mid level warm advection attendant to a veering 40-50 kt LLJ is fostering some spotty convection into portions of eastern Iowa, and also further south into northeast Missouri on the backside of a well defined convectively augmented wave shifting toward central Illinois. For this morning, we'll maintain spotty convection chances through daybreak attendant to the aforementioned forcing mechanisms. This will be elevated activity and could bring an isolated marginally severe hail threat. Thereafter, there is considerable uncertainty on convective evolution the rest of today. The RAP model is most aggressive on supporting more scattered convection developing mid to late morning through early afternoon, and is mostly an outlier. Mid level water vapor imagery does seem to suggest another potential subtle wave lifting quickly up across OK/s KS, and distance/speed would bring this across this morning. With the EML in place should any convection occur during this timeframe it would remain elevated, but with heating could lead to increased potential for a few marginally severe cores with hail again the main threat. Low confidence exists on this round of precipitation potential late morning into afternoon, but it could have some big implications on what happens later this afternoon into evening.

The main focus for deep convection and a more significant severe weather risk it appears will be in the vicinity of the outflow boundary by late afternoon into this evening. However, just where this boundary is located and where the subsequent main corridor for a severe weather risk remains uncertain. If we do end up with more convection festering late morning and afternoon, it could help retard the northward movement of the outflow and bring more of the area north of I-80 in the threat for a few storms by late afternoon into evening with the EML likely limiting storm coverage. If we don't see much convection in the late morning and early afternoon, then we will likely see this boundary lift northward and it could mix or effectively jump northward to Hwy 20 or possibly even further north into s WI and far ne IA just north/northwest of the service area by late afternoon, with any convective threat in our far north or not too far outside of the area. The evolution of the boundary will play a big role in where this chance for later PM/evening severe storms will exist. Effective bulk shear of 40-50+ kt within a moderately unstable atmosphere generally characterized by MLCAPE of 1500-2500+ j/kg will be favorable for supercells, with the supercell vector largely perpendicular to the initiating outflow supporting discrete potential meaning there may not be many storms. The kinematic and thermodynamic environment look to be favorable for significant severe, particularly large to very large hail with large CAPE in the growth zone and steep mid level lapse rates over 8c/km, with also a tornado threat due to any boundary interaction / ingestion of enhanced low level SRH.

Aside from the significant severe risk within the vicinity of the remnant outflow late afternoon/evening. The rest of the area is likely to remain dominated by an EML. Later tonight, forcing for ascent is forecast to increase ahead of an approaching shortwave ejecting from the Great Basin area early this morning. Thus, we do anticipate a burgeoning of convection later in the evening and overnight. This looks to largely remain elevated with primarily a large hail threat. However, any congealing of convection in multi-cells could foster some strong, gusty wind potential as well.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 334 AM CDT Tue Apr 14 2026

For Wednesday through Friday, the active pattern will only continue as an upper-level longwave trough moves through the area Wednesday, followed by yet another one on Friday. We continue with a Slight Risk or level 2 of 5 risk areawide on Wednesday. There remains some uncertainty on the timing and severity on Wednesday, mainly due to the likelihood of ongoing convection owing to uncertainty on the extent of airmass recovery/destabilization by afternoon and evening. However, we will have more of a trigger for severe weather with a surface low and attendant cold front. If we can see sufficient destabilization occur then the potential is there for at least scattered storms to develop ahead of the low and cold front by mid to late afternoon through evening. Strong deep layer shear and vector orientation may support discrete supercells with large to very large hail and some tornado threat, before potentially growing upscale into a QLCS with predominantly a damaging wind threat and potential for spin-up tornadoes with any mesovorts.

Thursday looks to be a drier and brief respite from the active weather, as a weak surface ridge traverses the region.

The break in the quiet is short-lived as the high moves off by Friday and we see strengthening return flow/warm advection on gusty southerly winds. The main focus for convective initiation on Friday is favored to our west ahead of a lifting surface low and attendant cold front. There is some potential for discrete supercells developing and/or propagating into parts of eastern Iowa Friday evening with all hazards possible. However, we may once again see this activity grow upscale into a QLCS with an accompanying damaging wind and spin-up tornado threat by mid to late evening and into the early overnight. Due to the risk for discrete supercells, SPC has introduced a 30% (enhanced) risk for portions of eastern Iowa and northeast Missouri.

A look ahead to the upcoming weekend shows a drier pattern developing for Saturday and Sunday as upper-level ridging develops to the west. A cold front should bring notably cooler and more seasonal temperatures to the area on the heels of strong, gusty northwest winds. This could bring our first bout of frost/freeze conditions during this growing season, possibly Saturday night though winds may stay up to limit this to just a freeze potential for parts of the area, while Sunday night could bring about more widespread freeze and frost with lighter winds as high pressure builds in.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1240 AM CDT Tue Apr 14 2026

Outflow boundary from convection across WI/far northeast IA will pass through KDBQ at the start of the TAFs bringing gusty northwest winds to 30 kt before veering to easterly and diminishing. PROB30 for a shower or storm will also exist behind the boundary for a short time at KDBQ at the start of the period while some lowering of MVFR ceilings looks likely. Across the rest of the terminals, predominantly VFR conditions pre-boundary overnight with gusty south/southwest winds. A strengthening LLJ will bring some marginal LLWS prior to daybreak. There is also a chance (20%) for a few showers/storms after 09z through 12z near/north of KMLI to south of KDBQ.

A period of MVFR to possibly localized IFR in low clouds and/or light fog exists Tuesday morning near KDBQ and possibly KCID near/north of the outflow boundary. Elsewhere, predominantly VFR conditions are expected the rest of the day on Tuesday. There is some signal for additional scattered higher based shower and storms late morning and early afternoon. However, this potential is lower confidence as consensus in the CAM guidance is lacking.

There is the potential for more storms Tuesday late afternoon and evening, with the signal mainly north of Hwy 30 in closer proximity to the retreating boundary. Will have PROB30 mention at KDBQ where confidence is higher. Elsewhere, a capping inversion and lack of a coherent trigger lends to confidence being too low for any mention.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.